Motor having terminals with unified shapes for positioning

ABSTRACT

The present invention may provide a motor including a shaft, a rotor coupled to the shaft, a stator disposed outside the rotor, and a bus bar disposed on the stator, wherein the bus bar includes a terminal connected to a coil of the stator, the terminal includes a first terminal and a second terminal which are separated from each other in a circuit manner, the first terminal includes a first neutral terminal and a plurality of first phase terminals, the second terminal includes a second neutral terminal and a plurality of second phase terminals, first curvature centers of the plurality of first phase terminals are disposed to be different, second curvature centers of the plurality of second phase terminals are disposed to be different, and a position of a curvature center of the first neutral terminal is the same as a position of a curvature center of the second neutral terminal.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

This application is a U.S. National Stage Application under 35 U.S.C. §371 of PCT Application No. PCT/KR2018/016753, filed Dec. 27, 2018, whichclaims priority to Korean Patent Application No. 10-2018-0001648, filedJan. 5, 2018, whose entire disclosures are hereby incorporated byreference.

TECHNICAL FIELD

The present invention relates to a motor.

BACKGROUND ART

Electronic power steering (EPS) systems secure turning stability ofvehicles and provide quick reinforcing force so that drivers can stablytravel. An EPS system uses an electronic control unit (ECU) to drive amotor according to driving conditions detected by a speed sensor, atorque angle sensor, a torque sensor, and the like so as to controloperation of a steering shaft of a vehicle.

A motor includes a rotor and a stator. A coil is wound around thestator. A connection end of the coil wound around the stator may beconnected to a bus bar. The bus bar includes a body and a terminal. Theterminal is connected to the connection end of the coil. In addition,the terminal may be connected to an external power source through acable.

The terminal may be formed as a combination of phase terminals connectedto U-phase, V-phase, and W-phase power sources and a neutral terminalconnecting the phase terminals. In this case, two terminals combined asdescribed above may be disposed and separated in a circuit to securesafety of a motor. In a case in which abnormality occurs in a circuit orelement connected to any one terminal, the motor can be driven throughthe other terminal. The two terminals are spatially separated frombodies of the bus bar.

However, since connection ends of the terminals are disposed atequidistant intervals, terminals having various shapes may be required.In the case in which the terminals have various shapes, there areproblems in that the number of molds is increased, a cost is increased,material loss is high, and a manufacturing process is complicated. Inaddition, during a process of injection-molding the bus bar, there areproblems in that errors in position of two terminals may easily occur,and it is difficult to visually check whether a position of the neutralterminal or the phase terminal is correct.

Technical Problem

The present invention is directed to providing a motor in which shapesof terminals are unified, which allows correct positions of theterminals to be secured during a process of forming a bus bar, and whichallows an assembly process to be simplified.

Objectives that should be solved according to embodiments are notlimited to the above described objectives, and other objectives whichare not described above will be clearly understood by those skilled inthe art from the following specification.

Technical Solution

One aspect of the present invention provides a motor including a shaft,a rotor coupled to the shaft, a stator disposed outside the rotor, and abus bar disposed on the stator, wherein the bus bar includes a terminalconnected to a coil of the stator, the terminal includes a firstterminal and a second terminal which are separated from each other in acircuit manner, the first terminal includes a first neutral terminal anda plurality of first phase terminals, the second terminal includes asecond neutral terminal and a plurality of second phase terminals, firstcurvature centers of the plurality of first phase terminals are disposedto be different, second curvature centers of the plurality of secondphase terminals are disposed to be different, and a position of acurvature center of the first neutral terminal is the same as a positionof a curvature center of the second neutral terminal.

A position of the first curvature center may be different from aposition of the second curvature center.

When a virtual line passing through the curvature center of the firstneutral terminal is referred to as a first reference line and when avirtual line perpendicular to the first reference line and passingthrough the curvature center of the first neutral terminal is referredto as a second reference line, the first curvature center may bedisposed at any one side of the first reference line, the secondcurvature center may be disposed at the other side of the firstreference line, and the first curvature center and the second curvaturecenter may be disposed at any one side of the second reference line.

When a virtual line passing through the curvature center of the firstneutral terminal is referred to as a first reference line and when avirtual line perpendicular to the first reference line and passingthrough the curvature center of the first neutral terminal is referredto as a second reference line, the first curvature center may bedisposed at any one side of the first reference line, the secondcurvature center may be disposed at the other side of the firstreference line, the first curvature center may be disposed at any oneside of the second reference line, and the second curvature center maybe disposed at the other side of the second reference line.

The first curvature center and the second curvature center may bedisposed to be rotationally symmetrical with respect to the curvaturecenter of the first neutral terminal.

The first curvature center and the second curvature center may bedisposed to be point-symmetrical with respect to the curvature center ofthe first neutral terminal.

Each of the first phase terminals and the second phase terminals mayinclude a body and protruding portions bent from the body in a radialdirection with respect to the curvature center of the first neutralterminal.

The first neutral terminal and the second neutral terminal may bedisposed to be point-symmetrical with respect to the curvature center ofthe first neutral terminal.

Each of the first phase terminals and the second phase terminals mayhave a multilayer structure, and the protruding portion disposed on asecond layer portion may be disposed to cross an upper side of the bodydisposed on a first layer portion.

When viewed in an axial direction, any one of the plurality ofprotruding portions disposed on any one of the plurality of first phaseterminals may be disposed between one side end portion of the firstneutral terminal and one side end portion of second neutral terminal,and any one of the plurality of protruding portions disposed on any oneof the plurality of second phase terminals may be disposed between theother side end portion of the first neutral terminal and the other sideend portion of the second neutral terminal.

The protruding portions may include a first end portion extending fromthe body in the radial direction, a second end portion protruding fromthe first end portion and electrically connected to the coil of thestator, and a third end portion branched off from the second end portionand electrically connected to a power cable.

Each of the first phase terminals and the second phase terminals mayinclude a body and a protruding portion bent from the body in a radialdirection with respect to the curvature center of the first neutralterminal, wherein the protruding portion may include a first end portionextending from the body in the radial direction, a second end portionprotruding from the first end portion and electrically connected to thecoil of the stator, and a third end portion branched off from the secondend portion and electrically connected to a power cable, and the secondend portion of the first phase terminal and the second end portion ofthe second phase terminal may be disposed to be rotationally symmetricalwith respect to the first curvature center.

Advantageous Effects

According to embodiments, since terminals having the same shape arecombined and formed to be connected to two divided circuits,advantageous effects are provided in that correct positions of theterminals are secured during a process of forming a bus bar, and anassembly process is simplified.

Although the plurality of terminals have the same shape, it is easy toarrange protruding portions of the terminals at equidistant intervals,and thus an advantageous effect of improving insulation stability isprovided.

DESCRIPTION OF DRAWINGS

FIG. 1 is a side cross-sectional view illustrating a motor according toan embodiment.

FIG. 2 is a perspective view illustrating a bus bar illustrated in FIG.1.

FIG. 3 is a view illustrating a terminal of the bus bar illustrated inFIG. 2.

FIG. 4 is a view illustrating a neutral terminal illustrated in FIG. 3.

FIG. 5 is a view illustrating a phase terminal illustrated in FIG. 3.

FIG. 6 is a view illustrating a curvature center of the neutralterminal.

FIG. 7 is a view illustrating a curvature center of the phase terminal.

FIG. 8 is a plan view of terminals to illustrate a position of aprotruding portion of the phase terminal.

FIG. 9 is an enlarged view illustrating the terminal illustrated in FIG.3.

FIG. 10 is a view illustrating a modified example of the terminal of thebus bar illustrated in FIG. 2.

FIG. 11 is a view illustrating a first phase terminal and a second phaseterminal which are rotationally symmetrical in the terminal illustratedin FIG. 10.

MODES OF THE INVENTION

Hereinafter, exemplary embodiments of the present invention will bedescribed with reference to the accompanying drawings in detail.Purposes, specific advantages, and novel features of the invention willbe made clear from the exemplary embodiments and the following detaileddescription in connection with the accompanying drawings. In thedescription of the invention, when it is determined that detaileddescriptions of related well-known functions unnecessarily obscure thegist of the invention, the detailed descriptions thereof will beomitted.

It will be understood that, although the terms “first,” “second,” etc.may be used herein to describe various elements, these elements shouldnot be limited by these terms. These terms are only used to distinguishone element from another. For example, a first element could be termed asecond element, and a second element could similarly be termed a firstelement without departing from the scope of the present invention. Asused herein, the term “and/or” includes combinations or any one of aplurality of associated listed items.

FIG. 1 is a side cross-sectional view illustrating a motor according toan embodiment.

Referring to FIG. 1, the motor according to the embodiment may include ashaft 10, a rotor 20, a stator 30, and a bus bar 40.

The shaft 10 may be coupled to the rotor 20. When a current is supplied,an electrical interaction occurs between the rotor 20 and the stator 30,the rotor 20 is rotated, and the shaft 10 is rotated in conjunction withthe rotor. The shaft 10 may be connected to a steering shaft of avehicle and may transmit power to the steering shaft.

The rotor 20 is rotated due to the electrical interaction with thestator 30.

The rotor 20 may include a rotor core and a magnet. The rotor core maybe formed to have a shape in which a plurality of circular steel platesare stacked or formed to have one cylindrical shape. A hole to which theshaft 10 is coupled may be disposed at a center of the rotor core. Aprotrusion for guiding the magnet may protrude from an outercircumferential surface of the rotor core. The magnet may be attached tothe outer circumferential surface of the rotor core. A plurality ofmagnets may be disposed along a circumference of the rotor core atpredetermined intervals. The rotor 20 may include a can member whichfixedly surrounds the magnets so that the magnets are not separated fromthe rotor core and the magnets are prevented from being exposed.

Coils 31 may be wound around the stator 30 to induce an electricalinteraction with the rotor 20. A specific structure of the stator 30around which the coils 31 are wound will be described below. The stator30 may include a stator core including a plurality of teeth. An annularyoke portion is provided and the teeth around which a coil is wound froma yoke toward a center thereof may be provided in the stator core. Theteeth may be provided along an outer circumferential surface of the yokeportion at predetermined intervals. Meanwhile, the stator core may beprovided as a plurality of thin steel plates being stacked. In addition,the stator core may be provided as a plurality of divided cores beingcoupled or connected.

The bus bar 40 may be disposed on the stator 30. The bus bar 40 mayinclude a terminal in a body having an annular shape. In addition, theterminal of the bus bar 40 may include phase terminals connected toU-phase, V-phase, and W-phase power sources and a neutral terminalconnecting the phase terminals.

A housing 50 may accommodate the rotor 20 and the stator 30 therein.

A sensing magnet 60 is coupled to the shaft 10 to operate in conjunctionwith the rotor 20. The sensing magnet 60 is an apparatus configured todetect a position of the rotor 20.

A sensor configured to detect a magnetic force of the sensing magnet 60may be disposed on a printed circuit board 70. In this case, the sensormay be a Hall integrated circuit (IC). The sensor detects a change inN-pole and S-pole of the sensing magnet 60 and generates a sensingsignal.

FIG. 2 is a perspective view illustrating the bus bar illustrated inFIG. 1.

Referring to FIG. 2, the bus bar 40 includes terminals 41 and a body 42.The body 42 is a molding part formed through an injection moldingprocess. The body 42 includes a hole 40 a in a central portion thereof.The terminal 41 is disposed in the body 42, and a part of an end portionof the terminal 41 is disposed to be exposed from the body 42. The body42 may substantially have an annular shape. The body 42 may have astructure having a plurality of layers. For example, the body 42 mayhave a form in which a second layer portion 42 b is stacked on a part ofan upper surface of a first layer portion 42 a.

FIG. 3 is a view illustrating the terminals of the bus bar illustratedin FIG. 2, FIG. 4 is a view illustrating the neutral terminalillustrated in FIG. 3, and FIG. 5 is a view illustrating the phaseterminal illustrated in FIG. 3.

Referring to FIGS. 1 to 3, the terminals 41 may include a first terminal100 and a second terminal 200. The first terminal 100 and the secondterminal 200 are connected to the coils 31 of the stator 30 butseparated from each other in a circuit manner. In addition, the firstterminal 100 and the second terminal 200 are spatially separated anddisposed.

The first terminal 100 may include one first neutral terminal 110 andthree first phase terminals 120. The three first phase terminals 120 areconnected to phases (U-phase, V-phase, and W-phase) of a three-phasepower source. The second terminal 200 may also include one secondneutral terminal 210 and three second phase terminals 220. The threesecond phase terminals 220 are connected to the phases (U-phase,V-phase, and W-phase) of the three-phase power source. The three firstphase terminals 120 and the three second phase terminals 220 have thesame shape. Accordingly, the first and second phase terminals 120 and220 may be manufactured using one mold. In addition, the first neutralterminal 110 and the second neutral terminal 210 have the same shape.The first and second neutral terminals 110 and 210 may also bemanufactured using one mold. Since the first terminal 100 and the secondterminal 200 have the same shape and the phase terminals have the sameshape, there are advantages in that a manufacturing process is simpleand a manufacturing cost is reduced.

Referring to FIG. 4, each of the first and second neutral terminals 110and 210 may include a body 1 and protruding portions 2. The body 1 andthe protruding portions 2 may only be distinguished and describedaccording to shapes and functional properties and may be verticallyconnected as one member.

The body 1 is a belt type member having a curved surface. The first andsecond neutral terminals 110 and 210 are relatively longer than thefirst and second phase terminals 120 and 220. The protruding portion 2is formed to extend from the body 1 in a radial direction with respectto a center (a curvature center C0 of the first neutral terminal 110) ofthe bus bar 40. Each of the first and second neutral terminals 110 and210 may have a multilayer structure. The body 1 may be positioned on afirst layer portion F1 of each of the first and second neutral terminals110 and 210. The protruding portion 2 may be positioned on a secondlayer portion F2 of each of the first and second neutral terminals 110and 210. The protruding portion 2 is electrically connected to the coil31 (see FIG. 1) of the stator 30 (see FIG. 1). The protruding portion 2may be fused to the coil 31 of the stator 30.

Referring to FIG. 5, each of the first and second phase terminals 120and 220 may include a body 3 and protruding portions 4. The body 3 andthe protruding portions 4 may only be distinguished and describedaccording to shapes and functional properties and may be verticallyconnected as one member.

The body 3 is a belt type member having a curved surface. The first andsecond phase terminals 120 and 220 are relatively shorter than the firstand second neutral terminals 110 and 210. The protruding portions 4 mayinclude first end portions 4 a, second end portions 4 b, and a third endportion 4 c. The first end portion 4 a may be formed to extend from thebody 3 in the radial direction with respect to the center (the curvaturecenter C0 of the first neutral terminal 110) of the bus bar 40. Thesecond end portion 4 b protrudes from the first end portion 4 a. An endof the second end portion 4 b is bent in a hook shape to be connected tothe coil 31 (see FIG. 1) of the stator 30 (see FIG. 1). The second endportion 4 b may be fused to the coil 31 (see FIG. 1) of the stator 30(see FIG. 1). The third end portion 4 c may be branched off upward fromthe first end portion 4 a. The third end portion 4 c is electricallyconnected to a power cable. Each of the first and second phase terminals120 and 220 may have the multilayer structure. A part of the body 3 andthe second end portion 4 b may be positioned on the first layer portionF1 of each of the first and second phase terminals 120 and 220. Anotherpart of the body 3 and the first end portion 4 a may be positioned onthe second layer portion F2 of each of the first and second phaseterminals 120 and 220.

FIG. 6 is a view illustrating a curvature center of the neutralterminal, and FIG. 7 is a view illustrating a curvature center of thephase terminal.

Referring to FIG. 6, the curvature center C0 of each of the first andsecond neutral terminals 110 and 210 corresponds to a center of avirtual circle extending from an inner circumferential surface of thebody 1 and having a radius R1. Referring to FIG. 7, first and secondcurvature centers C1 and C2 of the first and second phase terminals 120and 220 correspond to centers of vertical circles extending from innercircumferential surfaces of the bodies 3 and having radiuses R2.

Referring to FIGS. 3 to 6, the first curvature center C1 of the firstphase terminal 120 is different from the second curvature center C2 ofthe second phase terminal 220. In addition, the curvature center C0 ofthe first neutral terminal 110 is the same as the curvature center C0 ofthe second neutral terminal 210. In addition, positions of curvaturecenters C1 a, C1 b, and C1 c of three first phase terminals 120A, 120B,and 120C of the first terminal 100 are different. In addition, positionsof curvature centers C2 a, C2 b, and C2 c of three second phaseterminals 220A, 220B, and 220C of the second terminal 200 are alsodifferent. This is to arrange and place six phase terminals having thesame shape and the protruding portions 2 and 4 of two neutral terminalshaving the same shape in a circumferential and radial direction of thebus bar 40.

Specifically, a position of the first curvature center C1 may bedistinguished from a position of the second curvature center C2 on thebasis of a first reference line L1 passing through the curvature centerC0 of the first and second neutral terminals 110 and 210. For example,the first terminal 100 and the second terminal 200 may be disposed suchthat the first curvature center C1 is positioned at any one side of thefirst reference line L1 and the second curvature center C2 is positionedat the other side of the first reference line L1. In this case, thepositions of the curvature centers C1 a, C1 b, and C1 c of the threefirst phase terminals 120A, 120B, and 120C are different. In addition,the positions of the curvature centers C2 a, C2 b, and C2 c of the threesecond phase terminals 220A, 220B, and 220C are also different.

Curvature radiuses of three first phase terminals 120A, 120B, and 120Care the same but the positions of the curvature centers C1 a, C1 b, andC1 c are different. The positions of the curvature centers C1 a, C1 b,and C1 c are determined such that the protruding portions 4 of the threefirst phase terminals 120A, 120B, and 120C are aligned with theprotruding portions 2 of the first neutral terminal 110 in thecircumferential and radius directions of the bus bar 40.

In addition, curvature radiuses of the three second phase terminals220A, 220B, and 220C are also the same but the positions of thecurvature centers C2 a, C2 b, and C2 c are different. The positions ofthe curvature centers C2 a, C2 b, and C2 c are determined such that theprotruding portions 4 of the three second phase terminals 220A, 220B,and 220C are aligned with the protruding portions 2 of the secondneutral terminal 210 in the circumferential and radius directions of thebus bar 40.

Meanwhile, the first neutral terminal 110 and the second neutralterminal 210 may be disposed to be rotationally symmetrical with respectto the curvature center C0 of the first neutral terminal 110. Forexample, the first neutral terminal 110 and the second neutral terminal210 may be disposed to be point-symmetrical with respect to thecurvature center C0 of the first neutral terminal 110 such that any oneof the first neutral terminal 110 and the second neutral terminal 210overlaps the other one when rotating 180°.

FIG. 8 is a plan view of the terminals to illustrate the position of theprotruding portion of the phase terminal.

Referring to FIG. 8, a line A1 of FIG. 8 is a reference line connectingone side end portion of the first neutral terminal 110 and the curvaturecenter C0 of the first neutral terminal 110, and a line A2 of FIG. 8 isa reference line connecting the other side end portion of the firstneutral terminal 110 and the curvature center C0 of the first neutralterminal 110.

In addition, a line B1 of FIG. 8 is a reference line connecting one sideend portion of the second neutral terminal 210 and the curvature centerC0 of the first neutral terminal 110, and a line B2 of FIG. 8 is areference line connecting the other side end portion of the secondneutral terminal 210 and the curvature center C0 of the first neutralterminal 110.

Any one of the protruding portions 4 of the first phase terminals 120A,120B, and 120C, for example, the protruding portion 4 disposed at anoutermost side among the protruding portions 4 of the first phaseterminals 120A, 120B, and 120C, may be disposed in a region S1corresponding to a region between the lines A1 and B1 on the basis ofthe circumferential direction of the bus bar 40.

In addition, any one of the protruding portions 4 of the second phaseterminals 220A, 220B, and 220C, for example, the protruding portion 4disposed at an outermost side among the protruding portions 4 of thesecond phase terminals 220A, 220B, and 220C, may be disposed in a regionS2 corresponding to a region between the lines A2 and B2 on the basis ofthe circumferential direction of the bus bar 40.

This is to align the protruding portions 2 (see FIG. 4) of the first andsecond neutral terminals 110 and 210 with the protruding portions 4 (seeFIG. 4) of the first and second phase terminals 120 and 220 in thecircumferential and radial directions of the bus bar 40.

FIG. 9 is an enlarged view illustrating the terminal illustrated in FIG.3.

Referring to FIGS. 4, 5, and 9, each of the first phase terminal 120 andthe second phase terminal 220 has the multilayer structure. Thefollowing description will be given on the basis of the first phaseterminal 120. The protruding portion 4 disposed on the second layerportion F2 of the first phase terminal 120 is disposed to cross an upperside of the body 3 disposed on the first layer portion F1 of the otherfirst phase terminal 120 or an upper side of the body 1 disposed on thefirst layer portion F1 of the first neutral terminal 110. This is so theplurality of phase terminals do not overlap each other or the phaseterminals do not overlap the neutral terminals at intersections.

FIG. 10 is a view illustrating a modified example of the terminals ofthe bus bar illustrated in FIG. 2.

Referring to FIG. 10, in terminals 41 according to the modified example,a position of a first curvature center C1 may be distinguished from aposition of a second curvature center C2 on the basis of a firstreference line L1 passing through a curvature center C0 of first andsecond neutral terminals 110 and 210. For example, a first terminal 100and a second terminal 200 may be disposed such that the first curvaturecenter C1 is positioned at any one side of the first reference line L1and the second curvature center C2 is disposed at the other side offirst reference line L1.

In addition, the position of the first curvature center C1 may bedistinguished from the position of the second curvature center C2 on thebasis of a second reference line L2 which passes through the curvaturecenter C0 of the first and second neutral terminals 110 and 210 and isperpendicular to the first reference line L1. For example, the firstterminal 100 and the second terminal 200 may be disposed such that thefirst curvature center C1 is positioned at one side of the secondreference line L2 and the second curvature center C2 is positioned atthe other side of the second reference line L2.

In this case, positions of curvature centers C1 a, C1 b, and C1 c ofthree first phase terminals 120A, 120B, and 120C are different. Inaddition, positions of curvature centers C2 a, C2 b, and C2 c of threesecond phase terminals 220A, 220B, and 220C are also different.

In addition, the first curvature center C1 and the second curvaturecenter C2 may be disposed to be rotationally symmetrical with respect tothe curvature center C0 of the first neutral terminal 110. For example,the first curvature center C1 and the second curvature center C2 may bepoint-symmetrical with respect to the curvature center C0 of the firstneutral terminal 110 such that any one of the first curvature center C1and the second curvature center C2 overlaps the other one when rotating180°.

FIG. 11 is a view illustrating the first phase terminal and the secondphase terminal which are rotationally symmetrical in the terminalsillustrated in FIG. 10.

Referring to FIG. 11, in the terminals 41 according to the modifiedexample, a first phase terminal 120 and a second phase terminal 220 maybe disposed to be rotationally symmetrical with respect to the curvaturecenter C0 of the first neutral terminal 110. For example, second endportions 4 b of the first phase terminal 120 and second end portions 4 bof the second phase terminal 220 are rotationally symmetrical.

The motor according to one exemplary embodiment of the present inventionhas been specifically described with reference to the accompanyingdrawings as described above.

The above-described embodiments should be considered in a descriptivesense only and not for purposes of limitation, and the scope of thepresent invention is defined not by the detailed description but by theappended claims. In addition, the scope of the present invention shouldbe interpreted to encompass all modifications and alterations derivedfrom meanings, the scope, and equivalents of the appended claims.

The invention claimed is:
 1. A motor comprising: a shaft; a rotorcoupled to the shaft; a stator disposed outside the rotor; and a bus bardisposed on the stator, wherein the bus bar includes a terminalconnected to a coil of the stator, the terminal includes a firstterminal and a second terminal which are separated from each other in acircuit manner, the first terminal includes a first neutral terminal anda plurality of first phase terminals, the second terminal includes asecond neutral terminal and a plurality of second phase terminals, firstcurvature centers of the plurality of first phase terminals are disposedto be different, second curvature centers of the plurality of secondphase terminals are disposed to be different, and a position of acurvature center of the first neutral terminal is the same as a positionof a curvature center of the second neutral terminal, wherein, when avirtual line passing through the curvature center of the first neutralterminal is referred to as a first reference line and when a virtualline perpendicular to the first reference line and passing through thecurvature center of the first neutral terminal is referred to as asecond reference line: the first curvature center is disposed at any oneside of the first reference line; the second curvature center isdisposed at the other side of the first reference line; the firstcurvature center is disposed at any one side of the second referenceline; and the second curvature center is disposed at the other side ofthe second reference line.
 2. The motor of claim 1, wherein a positionof the first curvature center is different from a position of the secondcurvature center.
 3. The motor of claim 1, wherein the first curvaturecenter and the second curvature center are disposed to be rotationallysymmetrical with respect to the curvature center of the first neutralterminal.
 4. The motor of claim 3, wherein the first curvature centerand the second curvature center are disposed to be point-symmetricalwith respect to the curvature center of the first neutral terminal. 5.The motor of claim 1, wherein each of the first phase terminals and thesecond phase terminals includes: a body; and protruding portions bentfrom the body in a radial direction with respect to the curvature centerof the first neutral terminal.
 6. The motor of claim 5, wherein thefirst neutral terminal and the second neutral terminal are disposed tobe point-symmetrical with respect to the curvature center of the firstneutral terminal.
 7. The motor of claim 1, wherein each of the firstphase terminals and the second phase terminals includes: a body; and aprotruding portion bent from the body in a radial direction with respectto the curvature center of the first neutral terminal, wherein theprotruding portion includes a first end portion extending from the bodyin the radial direction, a second end portion protruding from the firstend portion and electrically connected to the coil of the stator, and athird end portion branched off from the first end portion andelectrically connected to a power cable, and the second end portion ofthe first phase terminal and the second end portion of the second phaseterminal are disposed to be rotationally symmetrical with respect to thefirst curvature center.
 8. A motor comprising: a shaft; a rotor coupledto the shaft; a stator disposed outside the rotor; and a bus bardisposed on the stator, wherein the bus bar includes a terminalconnected to a coil of the stator, the terminal includes a firstterminal and a second terminal which are separated from each other in acircuit manner, the first terminal includes a first neutral terminal anda plurality of first phase terminals, the second terminal includes asecond neutral terminal and a plurality of second phase terminals, firstcurvature centers of the plurality of first phase terminals are disposedto be different, second curvature centers of the plurality of secondphase terminals are disposed to be different, and a position of acurvature center of the first neutral terminal is the same as a positionof a curvature center of the second neutral terminal, wherein each ofthe first phase terminals and the second phase terminals includes: abody; and protruding portions bent from the body in a radial directionwith respect to the curvature center of the first neutral terminal,wherein: each of the first phase terminals and the second phaseterminals has a multilayer structure; and the protruding portiondisposed on a second layer portion is disposed to cross an upper side ofthe body disposed on a first layer portion.
 9. The motor of claim 8,wherein, when a virtual line passing through the curvature center of thefirst neutral terminal is referred to as a first reference line and whena virtual line perpendicular to the first reference line and passingthrough the curvature center of the first neutral terminal is referredto as a second reference line: the first curvature center is disposed atany one side of the first reference line; the second curvature center isdisposed at the other side of the first reference line; and the firstcurvature center and the second curvature center are disposed at any oneside of the second reference line.
 10. The motor of claim 8, wherein,when a virtual line passing through the curvature center of the firstneutral terminal is referred to as a first reference line and when avirtual line perpendicular to the first reference line and passingthrough the curvature center of the first neutral terminal is referredto as a second reference line: the first curvature center is disposed atany one side of the first reference line; the second curvature center isdisposed at the other side of the first reference line; the firstcurvature center is disposed at any one side of the second referenceline; and the second curvature center is disposed at the other side ofthe second reference line.
 11. The motor of claim 8, wherein theprotruding portions include: a first end portion extending from the bodyin the radial direction; a second end portion protruding from the firstend portion and electrically connected to the coil of the stator; and athird end portion branched off from the first end portion andelectrically connected to a power cable.
 12. A motor comprising: ashaft; a rotor coupled to the shaft; a stator disposed outside therotor; and a bus bar disposed on the stator, wherein the bus barincludes a terminal connected to a coil of the stator, the terminalincludes a first terminal and a second terminal which are separated fromeach other in a circuit manner, the first terminal includes a firstneutral terminal and a plurality of first phase terminals, the secondterminal includes a second neutral terminal and a plurality of secondphase terminals, first curvature centers of the plurality of first phaseterminals are disposed to be different, second curvature centers of theplurality of second phase terminals are disposed to be different, and aposition of a curvature center of the first neutral terminal is the sameas a position of a curvature center of the second neutral terminal,wherein each of the first phase terminals and the second phase terminalsincludes: a body; and protruding portions bent from the body in a radialdirection with respect to the curvature center of the first neutralterminal, wherein, when viewed in an axial direction: any one of theprotruding portions disposed on any one of the plurality of first phaseterminals is disposed between one side end portion of the first neutralterminal and one side end portion of the second neutral terminal; andany one of the protruding portions disposed on any one of the pluralityof second phase terminals is disposed between the other side end portionof the first neutral terminal and the other side end portion of thesecond neutral terminal.